Christopher Gray wrote in 2004 that the mansion resembled the Isaac D. Fletcher House, "although it edges toward a simpler expression, with somewhat less detail". After the List Building was completed in 1963, one guidebook characterized the original mansion and the newer building as "a French chateau with a Miami Beach annex". Shortly after the List Building opened, architectural critic Ada Louise Huxtable wrote that the two structures had been "joined in a shotgun architectural marriage, but will never speak to each other architecturally". Huxtable subsequently wrote in 1979: "I only wish that the Warburg house didn't seem so unloved." The 1993 addition, designed by Roche in imitation of Gilbert's style, had a mixed reception. When the plans for the annex were first announced, members of the Municipal Art Society expressed both satisfaction and displeasure over the new design. Some members praised it as a "modest and appropriate" addition complementing the original mansion, but others said the annex was "unimaginative and does nothing to show the evolution of design in our time". The completed work was favorably received by the general public. However, critics noted that while the annex was not distinguishable from the original building, it "lacked depth". Benjamin Forgey of The Washington Post wrote: "This pleasing if unexciting design is surprising mainly because of who did it," since Roche was better known as a modern architect. References Sources External links Warburg, Felix C. P. H. Gilbert buildings Fifth Avenue Houses on the National Register of Historic Places in Manhattan Gothic Revival architecture in New York (state) Houses in Manhattan Upper East Side Warburg family Châteauesque architecture in the United States New York City Designated Landmarks in Manhattan 1908 establishments in New York City Gilded Age mansions